Pool cleaning robot and a removable element

ABSTRACT

A method and a pool cleaning robot that may include a housing; an opening formed in the housing; an impeller that is configured to rotate and to induce fluid to flow through the pool cleaning robot; a filter for filtering fluid that flows through the pool cleaning robot; and wherein at least one of element the filter and the impeller is configured to exit the pool cleaning robot through the opening.

RELATED APPLICATIONS

This application is a continuation of U.S. patent application Ser. No.15/870,956 filing date Jan. 14, 2018 which is a continuation of U.S.patent application Ser. No. 14/433,859 filing date Apr. 7, 2015 which isa national phase application of PCT patent application serial numberPCT/IL2013/051055 international filing date Dec. 22, 2013 which claimspriority from U.S. provisional patent Ser. No. 61/745,556 filing dateDec. 22, 2012, all being incorporated herein by reference.

FIELD OF THE INVENTION

This invention relates to pool cleaning robots, and particularly toautonomous pool cleaning robots.

BACKGROUND OF THE INVENTION

Pool cleaning robots are adapted for use for cleaning a pool while beingconnected to electrical power cables or to a hose of a suction system.The hose and/or power cable can get tangled and may temporarily limitthe usage of the pool.

Once a filter of a pool cleaning robot is clogged the pool cleaningrobot is manually taken out of the pool and its filter can be washed bya user of the pool cleaning robot.

Taking a pool cleaning robot out of the pool is a time and effortconsuming operation that is not very fond by the users. In many casesthe users delay these manual operations or even skip them causing thepool cleaning robot to operate in a sub-optimal manner.

There is a growing need to provide autonomous robots that require alesser amount of human intervention in their maintenance.

SUMMARY OF THE INVENTION

There may be provided a pool cleaning robot and a method assubstantially illustrated in the specification and/or claims and/ordrawings.

BRIEF DESCRIPTION OF THE DRAWINGS

In order to understand the invention and to see how it may be carriedout in practice, an embodiment will now be described, by way of anon-limiting example only, with reference to the accompanying drawings,in which:

FIG. 1 illustrates a pool cleaning robot and an underwater stationaccording to an embodiment of the invention;

FIG. 2A illustrates a portion of a pool, a pool cleaning robot and adrain of the pool according to an embodiment of the invention;

FIG. 2B illustrates a portion of a pool and a pool cleaning robot thatis positioned on top of a drain of the pool according to an embodimentof the invention;

FIG. 2C illustrates a portion of a pool cleaning robot that ispositioned on top of a drain of the pool according to an embodiment ofthe invention;

FIG. 3A illustrates a portion of a pool, a pool cleaning robot and anunderwater station according to an embodiment of the invention;

FIG. 3B illustrates a portion of a pool and pool cleaning robot that iswirelessly charged by an underwater station while being positioned on aplatform of the underwater station according to an embodiment of theinvention;

FIG. 4A illustrates a portion of a pool, a pool cleaning robot, anunderwater station, a turbine, an electrical generator that feeds theunderwater station and a tube of a pool fluid circulation systemaccording to an embodiment of the invention;

FIG. 4B illustrates a portion of a pool, a pool cleaning robot, anunderwater station, a turbine, an electrical generator that form a partof the underwater station and a tube of a pool fluid circulation systemaccording to an embodiment of the invention;

FIG. 4C illustrates a portion of a pool, a pool cleaning robot thatincludes a turbine and an electrical generator and a tube of a poolfluid circulation system according to an embodiment of the invention;

FIG. 5A illustrates a pool cleaning robot that includes multiple filtersaccording to an embodiment of the invention;

FIG. 5B illustrates a bottom of a housing of a pool cleaning robot thatincludes multiple filters according to an embodiment of the invention;

FIG. 5C illustrates a pool cleaning robot that includes a filteraccording to an embodiment of the invention;

FIG. 6A illustrates a pool cleaning robot, an underwater station andmultiple filters according to an embodiment of the invention;

FIG. 6B illustrates a pool cleaning robot, an underwater station andmultiple filters according to an embodiment of the invention;

FIG. 7A illustrates an underwater station that comprises a filtermanipulator according to an embodiment of the invention;

FIG. 7B illustrates an underwater station that comprises a filtermanipulator that elevates a filter to be inserted into a pool cleaningrobot according to an embodiment of the invention;

FIG. 7C illustrates an underwater station that comprises a filtermanipulator and pool cleaning robot that is positioned on a platform ofthe underwater station and is fed by a filter according to an embodimentof the invention;

FIG. 7D illustrates an underwater station that comprises a filtermanipulator and pool cleaning robot that is positioned on a platform ofthe underwater station after being fed by a filter according to anembodiment of the invention;

FIG. 8 illustrates a pool cleaning robot that comprises a filteraccording to an embodiment of the invention;

FIG. 9 illustrates a filter having a filter core with a zigzag shapedarray of filtering elements, a perforated pole and a gear that assist inrotating a core of the filter according to an embodiment of theinvention;

FIG. 10 illustrates a filter a filter core with zigzag shaped array offiltering elements, a gear and a perforated pole that assist in rotatingthe filter and a filter core rotator according to an embodiment of theinvention;

FIG. 11A illustrates a pool cleaning robot that includes multiplefilters, a gear and a filter core rotator according to an embodiment ofthe invention;

FIG. 11B illustrates multiple filters positioned within a pool cleaningrobot, a gear and a filter core rotator according to an embodiment ofthe invention;

FIG. 12 illustrates a filter, a gear and a perforated pole, a filtercore rotator while the filter core is being inserted to (or extractedfrom) the filter housing according to an embodiment of the invention;

FIG. 13A illustrates a filter, a gear, a perforated pole, choppers, anda filter core rotator according to an embodiment of the invention;

FIG. 13B illustrates a bottom of the perforated pole and choppersaccording to an embodiment of the invention;

FIG. 14 illustrates a filter having a filter core that includes a finefiltering element and a coarse filtering element, a gear, a perforatedpole, and a filter core rotator according to an embodiment of theinvention;

FIG. 15 illustrates a filter having a filter core that includes afiltering element and blades, a gear, a perforated pole, choppers and afilter core rotator according to an embodiment of the invention;

FIG. 16A illustrates a filter having a filter core that includes azigzag shaped array of filtering elements, a perforated pole, amotor/generator that functions as a motor and acts as a filter corerotator and a turbine rotator, a rotor that acts as a turbine and ispositioned below the filter and an enclosure that has a first openingbelow the turbine and a second opening that is selectively sealed by auni-directional valve;

FIG. 16B illustrates a filter having a filter core that includes azigzag shaped array of filtering elements, a perforated pole, amotor/generator that functions as a generator, a rotor that acts as animpeller and is positioned below the filter and an enclosure that has afirst opening below the turbine and a second opening that is selectivelysealed by a uni-directional valve;

FIG. 17A is a cross sectional view of a filter having a filter core, aperforated pole, a motor/generator that functions as a motor and acts asa filter core rotator and a turbine rotator, a rotor that acts as aturbine and is positioned below the filter and an enclosure that has afirst opening below the turbine and a second opening that is selectivelysealed by a uni-directional valve;

FIG. 17B is a cross sectional view of a filter having a filter core, aperforated pole, a motor/generator that functions as a generator, arotor that acts as an impeller and is positioned below the filter and anenclosure that has a first opening below the turbine and a secondopening that is selectively sealed by a uni-directional valve;

FIG. 17C is a cross sectional view of a pool cleaning robot according toan embodiment of the invention;

FIG. 17D is a cross sectional view of a pool cleaning robot according toan embodiment of the invention;

FIG. 17E is a cross sectional view of a filter having a filter core, aperforated pole, a motor/generator that functions as a motor and acts asa filter core rotator and a turbine rotator, a rotor that acts as aturbine and is positioned above the filter and an enclosure that has afirst opening below the turbine and a second opening that is selectivelysealed by a uni-directional valve;

FIG. 17F is a cross sectional view of a filter having a filter core, aperforated pole, a motor/generator that functions as a generator, arotor that acts as an impeller and is positioned above the filter and anenclosure that has a first opening below the turbine and a secondopening that is selectively sealed by a uni-directional valve;

FIG. 18A illustrates various components of a pool cleaning robotaccording to an embodiment of the invention;

FIG. 18B illustrates power supply modules of a pool cleaning robotaccording to various embodiments of the invention;

FIG. 18C illustrates drive and steering modules a pool cleaning robotaccording to various embodiments of the invention;

FIG. 18D illustrates fluid control modules of a pool cleaning robotaccording to various embodiments of the invention;

FIG. 18E illustrates sensors of a sensing and communication module of apool cleaning robot according to various embodiments of the invention;

FIG. 18F illustrates various components of a pool cleaning robotaccording to an embodiment of the invention;

FIG. 18G illustrates various components of a pool cleaning robotaccording to an embodiment of the invention;

FIG. 18H illustrates various components of a pool cleaning robotaccording to an embodiment of the invention;

FIG. 19A illustrates various components of an underwater stationaccording to an embodiment of the invention;

FIG. 19B illustrates various components of an underwater stationaccording to an embodiment of the invention;

FIG. 20 illustrates a pool, a poll pool cleaning robot and a pool fluidcirculation system according to an embodiment of the invention;

FIG. 21 illustrates a method according to an embodiment of theinvention; and

FIG. 22 illustrates a method according to an embodiment of theinvention.

DETAILED DESCRIPTION OF EMBODIMENTS

According to various embodiments of the invention there is provided apool cleaning robot that is autonomous.

The pool cleaning robot can be being charged while being underwater.

Contactless Underwater Charging of a Pool Cleaning Robot

FIGS. 1 and 3A illustrate a pool cleaning robot 100 that approaches anunderwater station 200 according to an embodiment of the invention. FIG.3B illustrates a pool cleaning robot 100 that is mounted on anunderwater station 200 according to an embodiment of the invention.

The underwater station of FIG. 1 is illustrated as including an erectportion 230, a platform 230 on which the pool cleaning robot can mount,a first contactless charging element 210, and radiation sources 241 and242. Radiation sources 241 and 242 may be spaced apart from each otherand are arranged to emit radiation (such as ultrasonic radiation) thatcan be detected by sensor 110 of pool cleaning robot 100 and allow thepool cleaning robot 100 to navigate towards the underwater station 200.The pool cleaning robot 100 may compare between the radiation receivedfrom the different radiation sources (241 and 242) and direct itselftoward the underwater station 200. The radiation sources 241 and 242 mayemit radiation of different frequencies, in different points of time andthe like.

The platform 230 is illustrated as including flat surface 221 and rails222 that ease the mounting of the pool cleaning robot on the flatsurface 221. A first contactless charging element 210 may be connectedto the platform 220, embedded in the platform 220 or otherwise includedin the underwater station 200 and may be used to charge the poolcleaning robot 100 that in turn has a second contactless chargingelement (denoted 150 in FIGS. 3A and 3B) to facilitate the contactlesscharging of the pool cleaning robot 100. FIGS. 3A and 3B also illustratea cable 402 that feeds the underwater station with electrical power.This electrical power can be supplied to the first contactless chargingelement 210.

FIG. 1 also illustrates a holding element such as ring 9 that can becontacted when the pool cleaning robot 100 is taken out of the pool.

Charging a Pool Cleaning Robot using a Flow of Fluid that Induced by aPool Fluid Circulation System

A pool cleaning robot may be charged using a flow of fluid that isinduced by a pool fluid circulation system. A turbine that is rotated bythe flow of fluid can be included in the pool cleaning robot (as shownin FIGS. 2A, 2B, 2C and 4C), can be included in an underwater station(as shown in FIG. 4B) or can be coupled to the underwater pool cleaningrobot (as shown in FIG. 4A).

FIG. 2C illustrates a pool cleaning robot 100 while FIGS. 2A and 2Billustrate the pool cleaning robot 100 a s well as a portion of a pool300 and a drain 302 of the pool according to an embodiment of theinvention. In FIG. 2A the pool cleaning robot 100 is near the drain 302while in FIG. 2B the pool cleaning robot is on top of the drain (notshown). FIG. 2A also illustrates a communication module 306 forcommunication with the pool cleaning robot 100.

Referring to FIG. 2C—pool cleaning robot 100 includes turbine 120,housing 104, first fluid opening 101 and second fluid opening 102 formedin the housing 104, electrical generator 122, pump motor 132, impeller133, rechargeable power source such as battery 135, drive motor 124 andfirst track 141. Non-limiting examples of additional and/or alternativecomponents and modules of the pool cleaning robot 100 are illustrated inFIGS. 18A-18H.

The turbine 120 is positioned above a first fluid opening 101 formed atthe bottom of the pool cleaning robot 100 and below second fluid opening102.

The turbine 120 is at least partially disposed within a fluid pathformed between the first fluid opening 101 so as to extract energy fromflow of fluid through the fluid path.

Electrical generator 122 is arranged to provide electrical power theretoand adapted to be driven by the turbine 120.

The rechargeable power source 135 is arranged to be charged by theelectrical generator 122 and to supply electrical power during at leastone period of time during which the turbine 120 does not extract energyfrom the flow of fluid.

When positioned in proximity of the drain 302, fluid is sucked fromsecond fluid outlet 102, through the fluid path and exits the poolcleaning robot via the first fluid opening 101 thereby rotating theturbine 120.

It is noted that charging the pool cleaning robot 100 by the drain 302is an example of charging the pool cleaning robot by a flow of fluidthat is induced by a pool fluid circulation system (denoted 333 in FIG.20A).

Yet for another example—pool cleaning robot may be located in proximity(or in contact with) an output of a tube (denoted 408 in FIG. 4C) of thepool fluid circulation system.

It is expected that the pool cleaning robot 100 needs to be relativelyproximate (few centimeters till few tenths of centimeters) from an inletor outlet of the pool fluid circulation system in order that asufficient amount of flow of fluid is induced to flow through the fluidpath and thereby rotating turbine 120.

Accordingly—the charging may occur when the pool cleaning robot 100 ispositioned in a certain location in which a flow level of fluid that iscirculated by a pool fluid circulation system is higher than a flowlevel of the fluid within a majority of the pool or even be the highestflow level in the pool. When positioned at the certain location thefluid that is circulated by the pool fluid circulation system passesthrough the fluid path formed in the pool cleaning robot.

FIG. 4A illustrates a portion of a pool 300, a pool cleaning robot 100,an underwater station 200, a turbine 404, an electrical generator 406that feeds the underwater station 200 with electrical power via cable401 and a tube 408 of a pool fluid circulation system according to anembodiment of the invention. Turbine 404 and electrical generator 406are submerged and do not belong to the underwater station 200 or to thepool cleaning robot 100. Tube 408 can direct a jet of fluid towardsturbine 404 or may such fluid from the pool. Turbine has an outlet 410for allowing fluid that is jetted by the tube 408 to enter the pooland/or to allow fluid sucked through tube 408 to enter turbine 404.

FIG. 4B illustrates a portion of a pool 300, a pool cleaning robot 100,an underwater station 200 as well as a turbine 404 and an electricalgenerator 406 that form a part of the underwater station 200 that feedsthe underwater station according to an embodiment of the invention.Turbine 404 is rotated by a flow of fluid induced by tube 408 of thepool fluid circulation system.

FIG. 4C illustrates a portion of a pool 300, tube 408 and a poolcleaning robot 100 that includes turbine 404 and electrical generator406 according to an embodiment of the invention. The turbine 404 isrotated by a flow of fluid induced by tube 408 of the pool fluidcirculation system. This may require the pool cleaning robot to directturbine 404 (facing one of the sides of the pool cleaning robot—but notits bottom) to be positioned near the opening of tube 408.

Underwater Filter Replacement

Additionally or alternatively, filters of the pool cleaning robot can beinserted to the pool cleaning robot underwater, ejected from the poolcleaning robot underwater, replaced underwater and/or processedunderwater. The insertion and/or the ejection and/or the replacement ofthe filters can be executed by the robot, by an underwater station of bya combination of both.

FIG. 5A illustrates a pool cleaning robot 100 that includes multiplefilters 170, 172 and 174 according to an embodiment of the invention.FIG. 5B illustrates a bottom of a housing 104 of a pool cleaning robot100 that includes multiple filters according to an embodiment of theinvention. FIG. 5C illustrates a pool cleaning robot 100 that includes asingle filter 170 according to an embodiment of the invention.

Filter 172 may be used to filter the fluid that passes through the poolcleaning robot 100—as may be regarded as being in a filtering position.The fluid may enter through fluid opening 117 (see FIG. 5B).

Filters 172 and 174 may be regarded as being in a non-filteringposition.

Alternatively—more than one of the filters 170, 172 and 174 can be usedfor concurrently filtering fluid that passes through the pool cleaningrobot 100.

Alternatively—filter 170 or filter 174 can be used for filtering whilefilter 172 is not be used for filtering—when positioned at the center ofthe pool cleaning robot 100.

Filters 170, 172 and 174 may be inserted through a first filter opening160 formed in the housing of the pool cleaning robot 100.

Filters 170, 172 and 174 may be ejected (outputted) from the poolcleaning robot through the first filter opening 160 or (As illustratedin FIGS. 5A and 5C)—through a second filter opening (denoted 162 formedin the housing of the pool cleaning robot 100).

Between insertion and ejection the filters of FIGS. 5A and 5C follow alinear path (delimited by rails 169) that is normal to the longitudinalaxis of the pool cleaning robot. It is noted that other paths(non-linear, other linear paths) can be provided.

Filter openings may be positioned in various locations of thehousing—including the bottom of the housing, the upper portion of thehousing or any side portions (sidewalls) of the housing. FIGS. 5A-5Cmerely illustrates a non-limiting of the locations of such filteropenings.

FIG. 5A also illustrates a sanitizing unit 72 that is arranged toirradiate a filter with ultraviolet radiation or perform any othersanitizing process.

Referring to FIG. 5C—first filter opening 160 is equipped with a firstdoor 164 and a spring mechanism 166 that allows the first door 164 toopen when a filter is inserted to the pool cleaning robot 100 and to beclosed (thereby closing the first filter opening 160) after the filteris inserted.

Second filter opening 162 is equipped with a second door 168 and aspring mechanism 169 that allows the second door 168 to open when afilter is extracted/ejected/outputted from the pool cleaning robot 100and to be closed (thereby closing the second filter opening 162) afterthe filter is extracted/ejected/outputted.

It is noted that a filter opening can be closed by the filter (or by thefilter housing)—as illustrated in FIG. 5A.

FIGS. 6A and 6B illustrates a pool cleaning robot 100, an underwaterstation 200 and multiple filters 176 and 177 according to an embodimentof the invention.

The pool cleaning robot 100 is mounted on the underwater station 200.Filters 176 are stored in a first filter storage module 272 and then fedto the pool cleaning robot 100 by a first filter manipulator that isrepresented by arm 261. Filters are ejected from the pool cleaning robot100 by the first filter manipulator (if the same movement used forinserting filters can also eject filters) or by a second filtermanipulator that is represented by arm 263 that pushes used filters intounderwater station housing 250.

FIGS. 6A and 6B also illustrate a compressor (represented by arm 265)that compresses a used filter before the used filter enters underwaterstation housing 250.

The underwater station 200 is further illustrated as includingunderwater station housing 250 and filter ejection module 240 from whichused filters can be ejected or otherwise taken outside the pool.

The underwater station 200 is illustrated as including a duct 240through which used filters can float, ejected or taken outside the pool.

The underwater station 200 may include processing elements locatedwithin the housing 250 (or outside the housing) for sanitizing,shredding, compressing, and/or attaching floating elements to usedfilters.

FIG. 7A-7D illustrate an underwater station 200 during various stages ofa loading process of a filter into a pool cleaning robot 100 accordingto an embodiment of the invention. FIGS. 7C and 7D also illustrate thepool cleaning robot 100 that is being loaded with a filter.

The underwater station 200 includes a filter manipulator that includes aarm 266 for elevating a filter from a filter storage module 270 that mayhave a radially symmetrical shape (annular, cylindrical and the like)that has multiple compartments 273 for storing multiple filters 176. Thefilter storage module 270 is rotated about its center by a movementmodule that has an axel denoted 274 for rotating the filter storagemodule 270 about its axis—thereby selecting a selected filter to beinserted to the pool cleaning robot 100 via an opening formed at thebottom of the housing of the pool cleaning robot. The selected filter ispositioned in proximity to arm 266 in order to allow arm 266 to elevatethe filter into the pool cleaning robot 100. FIG. 7A illustrates apositioning of a selected filter near arm 266. FIGS. 7B-7C illustratesphases in the lifting process and FIG. 7D shows the end of the liftingprocess.

An opposite process may be used to extract a used filter from the poolcleaning robot 100—the arm 266 contacts the filter and lowers it to anempty compartment of the filter storage module 270.

FIG. 8 illustrates a pool cleaning robot 100 that comprises a filtermanipulator 180 and multiple filters according to an embodiment of theinvention.

The filter manipulator 180 includes a filter storage module 182 that hasmultiple compartments for storing multiple filters. The filter storagemodule 182 may be have a radially symmetrical shape (annular,cylindrical and the like) and is rotated about its center by a movementmodule that has an axel denoted 184 for rotating the filter storagemodule 180 about its axis—thereby placing a selected filter in afiltering position.

The entire filter storage module 182 can be manually or automaticallyreplaced. The latter can be executed by an underwater station or by thepool cleaning robot itself.

Filter Having a Rotatable Core

According to various embodiments of the invention there are providedfilters that have filter cores that are rotatable. The rotation mayintroduce a centrifugal force that pushes compresses dirt towards theexterior of the filter and/or towards filtering elements of the filterand improves the filtering process.

FIG. 9 illustrates a filter 500 that includes a filter core 510, afilter core enclosure 530 and filter housing 540.

It is noted that in various figures (for example FIGS. 9, 10, 12, 13A,13B, 14, 15, 16A, 16B) there is illustrated a gap between the filterenclosure 530 and the filter housing 540. Such a gap may not exist orotherwise fluid can be prevented from passing through the gap unfilteredand enter various parts of the pool cleaning robot.

The filter core 510 is at least partially located within the filterhousing 540 and includes one or more inlets 511, one or more outlets 513and at least one filtering element (such as the zigzag array offiltering elements 516) that is positioned between the one or moreinlets 511 and the an one or more outlets 513. The filter core enclosure530 includes openings 532 that facilitate a flow of fluid to and fromthe filter core 510.

The filter core enclosure 530 includes a gear 518 that meshes withanother gear 550. The other gear may be rotatably connected to thefilter housing 540 and is rotated by a filter core rotator (denoted 552in FIG. 11B).

The filter housing 540 includes filter housing openings 542 thatfacilitates a flow of fluid to and from the filter core enclosure 530.

FIG. 9 illustrates a cylindrical shaped filter core enclosure and afilter housing having a cylindrical interior and a rectangular shapedexterior. The filter core 510, the filter enclosure 530 and the filterhousing 540 can be of different shapes.

FIG. 9 also illustrated a perforated pole 560 that is located at thecenter of the filter core 510. The perforated pole 560 can be regardedas belonging to filter 500 or as not belonging to the filter 500. Theperforated pole 560 can be attached to the filter 500 in a detachable ornon-detachable manner. For example an actuator and a spring may beprovided for detaching or locking the filter.

FIG. 10 illustrates filter 500 as having (or being connected to) aperforated pole 560 that is connected to axel 562 that has a gear 564 atits top. Gear 564 is rotated by another gear 554 connected to filtercore rotator 552. In FIG. 10 the filter housing 540 is not connected togear 550 and the filter enclosure 530 does not include a gear.

FIGS. 11A and 11B illustrate a pool cleaning robot 100 that includesmultiple filters 170, 172 and 174, a gear 550 of filter 172 that ispositioned in a filtering position and is rotated by filter core rotator552 according to an embodiment of the invention.

FIG. 12 illustrates filter 500 as having (or being connected to) aperforated pole 560 that is connected to axel 562 that has a gear 564 atits top. Gear 564 is rotated by another gear 554 connected to filtercore rotator 552. The filter core rotator 552 may be a pump motor, adrive motor or be mechanically coupled to one of these motors.

The filter core 510 can be inserted to (or extracted from) the filterhousing 540. The filter housing 540 can be part of the filter and/or canbe a part of the pool cleaning robot.

FIG. 13A illustrates a filter 500, a gear 550, a perforated pole 560,choppers 570, and a filter core rotator 552 according to an embodimentof the invention. FIG. 13B illustrates an area of filter 510 thatincludes choppers 570. The choppers 570 are connected to an input of theperforated pole 570 so then when the perforated core is rotated thechoppers chop debris that enters the filter 500 via the perforated pole560. The input of the perforated pole 560 can be positioned directlyabove an opening such as fluid opening 117 of FIG. 5B

Choppers 570 are shown as having fin like shape and are facing eachother. There may be one or more choppers. Different choppers 570 canhave different shapes and/or sizes.

The choppers can be connected to the filter core or other parts of thefilter. Choppers can be positioned at different heights of theperforated pole or filter.

The choppers may be attached as propellers to axle 558.

FIG. 14 illustrates filter 500 as having (or being connected to) aperforated pole 560 that is connected to axel 562 that has a gear 564 atits top. Gear 564 is rotated by another gear 554 connected to filtercore rotator 552. The filter core 510 includes filtering elements thatare a fine filter element 595 and a coarse (or gross) filtering element594 both are illustrated as being a cylindrical shaped meshes. Fluidfrom the one or more inlets of the filter are filtered by the grossfiltering element 594 before being filtered by the fine filteringelement 595. The gross and fine filtering elements by differ from eachother by the size of particles they block. The gross filtering mesh maybe constructed of 200 microns pore size and the fine mesh may be of 50microns pore size. Other pore sizes can be provided.

FIG. 15 illustrates filter 500 as having (or being connected to) aperforated pole 560 that is connected to axel 562 that has a gear 564 atits top. Gear 564 is rotated by another gear 554 connected to filtercore rotator 552. The filter 500 includes blades 577 that may beconnected to various other parts of the filter 510. Additionally oralternatively the blades 577 are connected to an inner cylindrical frame(not shown) that may be parallel to the perforated pole 560, may contactthe perforated pole 560, may be spaced apart from the perforated pole560, may be connected to and/or held by the filter core enclosure 530(for example—held by the floor, bottom and/or sidewall of the filtercore enclosure). When the perforated pole 560 is not connected to theblades and the filter core 510 the perforated pole 560 may remain in thepool cleaning robot after ejection of the filter core 510 andaccumulated dirt can be serviced efficiently and washed off the blades.The blades 557 may extend along the entire filter enclosure 530 and arepositioned between the perforated pole 560 and the filtering element594. The blades 577 form a rotor. When the filter core 510 is rotated byfilter core rotator 552 these blades may cause the filter core 510 toact as a turbine and assist the flow of water into the filter core.

Dual Mode Motor-Generator and Dual-Mode Rotor

FIGS. 16A, 17A and 17E illustrate a filter 500, a rotor 590 thatfunctions as an impeller, a motor/generator 559 that functions as amotor for rotating the filter core 510 and the rotor 590, and anenclosure 595 not shown that surrounds the rotor and has (a) a firstopening 102 located below the rotor 590 and (b) a second opening 593that is selectively sealed by a uni-directional valve 592, according toan embodiment of the invention. Alternatively, the first and secondopenings 102 and 593 may be formed in the bottom of the pool cleaningrobot 100 and the enclosure 595 may be located above the bottom in amanner that the bottom and the enclosure may provide a closedenvironment (except the openings 102 and 593).

In FIG. 16A the filter 500 is positioned between the rotor 590 and themotor/generator 559. In FIG. 17A the rotor 590 is positioned between thefilter 500 and the motor/generator 559. An axle/spindle 558 connects themotor/generator 559 to the perforated pole 560.

In this mode of operation fluid is directed by the rotor to enter thefilter 500 and to exit filter 500 after being filtered. In this mode ofoperation the uni-directional valve 592 seals the second opening 593.

In FIG. 17E the filter 500 (or the filter 500 and the rotor 590) can befed to the pool cleaning robot via opening 802 formed in a bottom 803 ofthe pool cleaning robot. Once inserted in the pool cleaning robotconnecting elements (such as elastic ring 801 placed in a space formedby connecting element 804 may hold the filter 500.

FIGS. 16B, 17B and 17F illustrate a filter 500, a rotor 590 thatfunctions as a turbine, a motor/generator 559 that functions as agenerator for generating electrical energy, and an enclosure 595 thatsurrounds the rotor and has a first opening 102 above the rotor 590 anda second opening 593 that is selectively sealed by a uni-directionalvalve 592, according to an embodiment of the invention.

Alternatively, the first and second openings 102 and 593 may be formedin the bottom of the pool cleaning robot 100 and the enclosure 595 maybe located above the bottom in a manner that the bottom and theenclosure may provide a closed environment (except the openings 102 and593).

In FIG. 16B the filter 500 is positioned between the rotor 590 and themotor/generator 559. In FIG. 17B the rotor 590 is positioned between thefilter 500 and the motor/generator 559.

In this mode fluid is sucked (for example by a drain of a pool) throughsecond opening 593 and rotates the rotor 590 that in turn rotatesmotor/generator 599. The uni-directional valve 592 is open.

In FIG. 17F the filter 500 (or the filter 500 and the rotor 590) can befed to the pool cleaning robot via opening 802 formed in a bottom 803 ofthe pool cleaning robot. Once inserted in the pool cleaning robotconnecting elements (such as elastic ring 801 placed in a space formedby connecting element 804 may hold the filter 500.

FIG. 17C is a cross sectional view of pool cleaning robot 100 accordingto an embodiment of the invention. The pool cleaning robot 100 includeshousing 104 filter 500, a rotor 590 that functions as an impeller, amotor/generator 559 that functions as a motor for rotating the filtercore (part of filter 500) and the rotor 590, electrical generator 122and turbine 120 that are spaced apart from filter 500 and are positionedabove another opening of the housing. In this mode of operation fluid isdirected by the rotor 590 to enter the filter 500 and to exit filter 500after being filtered. In this mode of operation a uni-directional valve(not shown) seals the opening below turbine 120.

FIG. 17D is a cross sectional view of pool cleaning robot 100 accordingto an embodiment of the invention. The pool cleaning robot 100 includeshousing 104 filter 500, a rotor 590 that functions as a turbine, amotor/generator 559 that functions as an electrical generator and therotor 590, an electrical generator 122 and turbine 120 that are spacedapart from filter 500 and are positioned above another opening of thehousing. The opening below the turbine 120 is opened and fluid is sucked(for example by drain 302 of a pool) through opening 102 into the poolcleaning robot and out of the pool cleaning robot to drain 302 therebyrotating the rotor 590 that in turn rotates motor/generator 599 androtating turbine 120.

Any one or a combination of the filter 500 and the rotor 590 of FIGS.16A, 16B, 17A, 17B, 17C, 17D, 17E and 17F can be replaced underwater (orabove the water) through openings formed in the pool cleaning robot.This is illustrated by opening 802 formed in the bottom of the housingin FIGS. 17E and 17F. The opening can be formed in sidewall of the poolcleaning robot. When any filter is provided into the pool cleaning robot(for example, any one of the filters illustrated in FIGS. 5A, 5C, 6A,6B, 7A, 7B, 7C, 7D, 12, 17E and 17F) it can be held to its position byany known fastening or holding element known in the art such as pins,blots, stripes, rails, springs and the like. Additionally oralternatively the opening through which the filter is inserted can closeor at least partially close the opening through which the filterentered. For example, after a filter has been inserted from the bottomof the pool cleaning robot, it may be fastened by vertical elements thatcontact the upper part of the filter, the filter opening may close, thefilter can be inserted into vertical or otherwise erect rails and thelike.

FIG. 18A illustrates various components of a pool cleaning robot 100according to an embodiment of the invention.

The pool cleaning robot 100 is illustrated as including controller 101,drive and steering module 20, power supply module 40, fluid controlmodule 30, sensing and communication module 50 and brushing module 90.

The controller 101 is arranged to control the operation of the poolcleaning robot 100 and especially control the various modules 20, 30, 40and 50. For example, the controller 101 may be arranged to navigate thepool cleaning robot 100 to direct the pool cleaning robot to bepositioned in a certain location in which a flow level of fluid that iscirculated by a pool fluid circulation system is higher than a flowlevel of the fluid within a majority of the pool (for example—to be inproximity to a drain of the pool), wherein when positioned at thecertain location the fluid that is circulated by a pool fluidcirculation system passes through a fluid path formed in the poolcleaning robot and thereby rotate a turbine.

FIG. 18B illustrates power supply modules 40 of a pool cleaning robot100 according to various embodiments of the invention.

The power supply module 40 is configured to provide electrical power tovarious power consuming components such as controller 101, motors,sensors, and the like. It may receive the electrical power or generateit.

One power supply module 40 includes a second contactless chargingelement 150 and a rechargeable power source 135 (see, for example FIGS.3A-3B and 4A-4C).

Another power supply module 40 includes a turbine 120, electricalgenerator 122 and a rechargeable power source 135 (see, for exampleFIGS. 2A-2C).

A further power supply module 40 includes a rotor 590 that acts as aturbine, a motor/generator 559 that acts as a generator and arechargeable power source 135 (see, for example FIGS. 16A-16B and17A-17B).

FIG. 18C illustrates drive and steering modules 20 of a pool cleaningrobot according to various embodiments of the invention.

Drive and steering module 20 is arranged to move the pool cleaning robot100. It may include one or more motors, one or more wheels or tracks andone or more transmissions that convey movements introduced by motors tothe one or more wheels and/or one or more tracks.

One drive and steering module 20 includes first drive motor 124, seconddrive motor 125, first transmission 127, second transmission 129, firsttrack 141 and second track 143. Some of these components are shown inFIGS. 1, 2A-2C, 3A-3C, 4A-4B and the like.

The pool cleaning robot 100 may include a brushing module (denoted 90 inFIG. 18A) that may include one or more brushing wheels such as brushingwheels 108 that are rotated (directly or indirectly) by first and secondtracks 141 and 143. The direction of movement of the pool cleaning robot100 can be controlled by individually controlling the movement of firstand second tracks 141 and 143.

Another drive and steering module 20 includes first drive motor 124,first transmission 127, first track 141, second track 143, brushingwheels (not shown) and steering elements 107. Steering elements 107 caninclude fins, imbalance introduction elements, controllable fluid jetelements and the like. Non-limiting examples of steering elements areprovided in U.S. patent application Ser. No. 14/023,544 filed Sep. 11,2013 which is incorporated herein by reference. Any other steeringelements known in the art can be used.

FIG. 18D illustrates fluid control modules 30 of a pool cleaning robotaccording to various embodiments of the invention.

A fluid control module 30 is arranged to control a flow of fluid withinthe pool cleaning robot and to filter said fluid.

It may include, any combination of the following:

-   -   a. Impeller 133 and pump motor 132 for inducing fluid to flow        through the pool cleaning robot 100 (see, for example FIG. 2C).    -   b. Rotor 590 that acts as an impeller and a motor/generator 559        that acts as a motor (see, for example, FIGS. 16A, 16B, 17A,        17B, 17C, 17D).    -   c. Filter 170, 172, 174 or 500. The filter may have, for        example, a filter core 510, a filter enclosure 530 and a filter        housing 540.    -   d. A filter core rotating element 552 (see, for example, FIGS.        10, 12 and 14).    -   e. Filter manipulator 180 (see, for example, FIG. 8).

FIG. 18E illustrates sensors of a sensing and communication module 50 ofa pool cleaning robot according to various embodiments of the invention.The sensing and communication module 50 may include one or more of thefollowing sensors:

-   -   a. Underwater station radiation sensor 110 for sensing radiation        from an underwater station (see, FIG. 1).    -   b. Ultrasonic transceiver 51 for sensing a flow of fluid in the        pool—that is expected to be relatively high near the drain of        other flow inducing elements of a pool fluid circulation system.    -   c. Acoustic sensor 52 that may include an acoustic emitter and        an acoustic detector to provide information about the area of        the pool the pool cleaning robot 100 is passing on.    -   d. Gyrocompass 53 or multiple gyrocompasses for providing        directional information.    -   e. Accelerometer 54.    -   f. Step counter 56 for measuring movement of the pool cleaning        robot.    -   g. Orientation sensor 56 for sensing the orientation of the pool        cleaning robot 100.    -   h. Communication unit 59 for communication with the underwater        station 200, or with other elements in the pool (see element 306        of FIG. 2A) or outside the pool.

FIG. 18F illustrates various components of a pool cleaning robot 100according to an embodiment of the invention. This is an example ofcombination of controller 101 and various components of the drive andsteering module 20, power supply module 40, fluid control module 30,sensing and communication module 50 and brushing module 90.

In FIG. 18F the pool cleaning robot 100 includes controller 101, sensingand communication module 50, filter 170, filter manipulator 180, filtercore rotating element 520, rechargeable power source 135, secondcontactless charging element 150, impeller 133, pump motor 132, firstand second drive motors 124 and 125, first and second transmissions 127and 129, first and second tracks 141 and 143.

FIG. 18G illustrates various components of a pool cleaning robot 100according to an embodiment of the invention.

In FIG. 18G the pool cleaning robot 100 includes controller 101, sensingand communication module 50, filter 170, filter manipulator 180,rechargeable power source 135, electrical generator 122, turbine 120,impeller 133, pump motor 132, first drive motor 124, steering elements107, first transmission 127, first and second tracks 141 and 143 andbrushing module 90.

FIG. 18H illustrates various components of a pool cleaning robot 100according to an embodiment of the invention.

This is an example of combination of controller 101, drive and steeringmodule 20, power supply module 40, fluid control module 30, sensing andcommunication module 50, brushing module 90 and a processing module 70.The processing module 70 is arranged to process filters (not shown). Theprocessing module 70 may include at least one out of: sanitizing unit 72that is arranged to irradiate a filter with ultraviolet radiation orperform any other sanitizing process, compressor 74 for compressing aused filter (for example—filter 174 of FIG. 5A), a shredder 76 forshredding a user filter a portion of the filter (its core), and a floatinducing module 78 for attaching a floating material (foam, balloon thatis inflated) to a user filter and the like.

The processing module 70 can be part of any of the pool cleaning robotsillustrated in any previous figures or in any other text of thespecification.

FIG. 19A illustrates various components of an underwater station 200according to an embodiment of the invention.

The underwater station 200 includes an underwater station controller740, an underwater station filter manipulation module 760, a sensing andcommunication module 720, a power supply module 207, and an underwaterprocessing module 700.

The underwater station controller 740 controls the various modules ofthe underwater station 200. It can, for example, use information fromsensing and communication module 720 for sensing when a pool cleaningrobot is positioned within a charging range from a first contactlesscharging element and control a provision of power to said firstcontactless charging element. It may initiate, control and stop a filterinsertion process to a pool cleaning robot and/or a filter ejectionprocess from a pool cleaning robot and the like.

The sensing and communication module 720 may include one or more sensorsfor sensing the location of the pool cleaning robot 100, the status ofvarious operations (processing filters, feeding or extracting filters)and the like. This information may be fed to the underwater stationcontroller 740. This module communicates with the pool cleaning robot orother devices in or outside the pool.

The power supply module 207 supplies power to the various modules of theunderwater station 200 and may also feed (in a contactless or a contactbased manner) a pool cleaning robot.

The underwater processing module 700 may perform at least one out of:sanitizing of pre-used or used filters, compressing used filters,shredding user filters attaching a floating material (foam, balloon thatis inflated) to a user filters and the like.

FIG. 19B illustrates various components of an underwater station 200according to an embodiment of the invention. This figure illustratesmultiple components per each module of the underwater station 200. Anycombination of any components can be provided.

The underwater station filter manipulation module 760 may include atleast one out of

-   -   a. In-housing manipulator 711 for manipulating filters within        housing 250.    -   b. Filter manipulators such as 260, 262 and 264. Each may        include movement modules (261, 263, 265 and 275) and storage        modules (272 and 270).        -   i. Filter manipulator 260 is arranged to store and            manipulate pre-used filters (including inserting the            pre-used filters to a pool cleaning robot 100, providing            and/or arranging filters to/within filter storage module            272, ejecting filters from a pool cleaning robot (see, arm            261 of FIGS. 6A and 6B).        -   ii. Filter manipulator 262 is arranged to store and            manipulate used-filters (extract from pool cleaning robot,            direct used filter towards housing and/or compressor or            other processing element). See, for example, FIGS. 6A-6B.        -   iii. Filter manipulator 264 is arranged to store and            manipulate filters. See, for example, FIGS. 7A-7D.

The sensing and communication module 720 may include at least one out ofweight sensor 721, ultrasonic transceiver 722, proximity sensor 723,cleanliness sensor 724 and communication unit 725. The sensors 721, 722,723 are arranged to sense the location of a pool cleaning robot 100and/or evaluate wherein the pool cleaning robot is positioned in adocking position in which it can be charged and/or receive or extractfilters. Cleanliness filter 724 may sense the cleanliness of pre-usedfilters and/or used filters. It may indicate that an extracted filter isclean enough to be used and cause the controller 740 to control aprocess of returning the used filter to the pool cleaning robot 100 viaone of the filter manipulators. The communication unit 725 may bearranged to communicate with the pool cleaning robot or other devices inor outside the pool. It may include, for example radiation sources 241and 242 of FIG. 1.

The power supply module 207 may include at least one of the following:

-   -   a. Electrical cable 402 (FIG. 3A).    -   b. Turbine 404 (FIG. 4B).    -   c. Electrical generator 406 (FIG. 2B).    -   d. Rechargeable power source 405.    -   e. First contactless charging element (such as a coil) 210 (see        FIG. 1).

The underwater processing module 700 may include at least one of thefollowing:

-   -   a. Ejector 707 for ejecting used filters from the underwater        station 200.    -   b. Floater 709 for attaching or otherwise associating a used        filter with floating materials (foam, inflated balloon).    -   c. Compressor 701 and/or 265 (see FIGS. 6A-6B).    -   d. Shredder 703.    -   e. Sanitizer 705.

FIG. 20A illustrates a pool 300, a pool cleaning robot 100 and a poolfluid circulation system that includes drain 302, fluid pipes 304,filter 330, temperature control unit 320 and circulating pump 310 andtube 408. Any type of pool fluid circulation system can be utilized forthe purposes of this invention. A pool can be regarded as a swimmingpool, any type of pool or any type of vessel, container, enclosure thatmay contain fluid.

Any combination of any components of any pool cleaning robot illustratedin any of the figures may be provided.

Any reference to any pool cleaning robot is applied mutatis mutandis toa method for operating the pool cleaning robot.

Any combination of any components of any underwater systems can beprovided.

Any reference to any underwater system is applied mutatis mutandis to amethod for operating the pool cleaning robot.

FIG. 21 illustrates method 400 according to an embodiment of theinvention.

Method 400 is autonomous operation. Method 400 includes step 410 ofperforming, by at least one of a pool cleaning robot and an underwaterstation, in an autonomous manner at least one out of pool cleaning robotfilter replacement and pool cleaning robot charging.

The term autonomous may mean without human intervention. The poolcleaning robot charging is applied on a pool cleaning robot that is notconstantly connected to a cord that extends outside the pool andconstantly supplies to the pool cleaning robot electrical energy orsupplied to the pool cleaning robot a constant a flow of fluid.

For example, executing the process at least partially illustrated in anyone of FIGS. 1, 2A, 2B, 2C, 3A, 3B, 4A, 4B may amount to performing inan autonomous manner a pool cleaning robot charging.

Yet for another example, executing the process at least partiallyillustrated in any one of FIGS. 6A, 6B, 7A, 7B, 7C, 7D, 8 and 12 mayamount to performing in an autonomous manner a pool cleaning robotfilter replacement.

FIG. 22 illustrates method 500 according to an embodiment of theinvention.

Method 500 includes stage 510 of filtering fluid by a pool cleaningrobot by using a filter that fulfils at least one of the following: (i)it has a filter core that is rotated by a filter core rotator when thefilter applied a filtering operation, (ii) is positioned in a filteringposition while at least one other filter of the pool cleaning robot ispositioned within the pool cleaning robot in a non-filtering position,(iii) is positioned in a filtering position when the pool cleaning robotand by a filter manipulator.

For example, the filtering can be executed by any one of the filtersillustrated in FIGS. 5A, 5C, 6A, 6B, 7A, 7B, 7C, 7D, 8, 9, 10, 11A, 11B,12, 13A, 13B, 16A, 16B, 17A-17F.

Moreover, the terms “front,” “back,” “top,” “bottom,” “over,” “under”and the like in the description and in the claims, if any, are used fordescriptive purposes and not necessarily for describing permanentrelative positions. It is understood that the terms so used areinterchangeable under appropriate circumstances such that theembodiments of the invention described herein are, for example, capableof operation in other orientations than those illustrated or otherwisedescribed herein.

Those skilled in the art will recognize that the boundaries betweenlogic blocks are merely illustrative and that alternative embodimentsmay merge logic blocks or circuit elements or impose an alternatedecomposition of functionality upon various logic blocks or circuitelements. Thus, it is to be understood that the architectures depictedherein are merely exemplary, and that in fact many other architecturesmay be implemented which achieve the same functionality.

Any arrangement of components to achieve the same functionality iseffectively “associated” such that the desired functionality isachieved. Hence, any two components herein combined to achieve aparticular functionality may be seen as “associated with” each othersuch that the desired functionality is achieved, irrespective ofarchitectures or intermedial components. Likewise, any two components soassociated can also be viewed as being “operably connected,” or“operably coupled,” to each other to achieve the desired functionality.

Furthermore, those skilled in the art will recognize that boundariesbetween the above described operations merely illustrative. The multipleoperations may be combined into a single operation, a single operationmay be distributed in additional operations and operations may beexecuted at least partially overlapping in time. Moreover, alternativeembodiments may include multiple instances of a particular operation,and the order of operations may be altered in various other embodiments.

Also for example, in one embodiment, the illustrated examples may beimplemented as circuitry located on a single integrated circuit orwithin a same device. Alternatively, the examples may be implemented asany number of separate integrated circuits or separate devicesinterconnected with each other in a suitable manner.

Also for example, the examples, or portions thereof, may implemented assoft or code representations of physical circuitry or of logicalrepresentations convertible into physical circuitry, such as in ahardware description language of any appropriate type.

However, other modifications, variations and alternatives are alsopossible. The specifications and drawings are, accordingly, to beregarded in an illustrative rather than in a restrictive sense.

In the claims, any reference signs placed between parentheses shall notbe construed as limiting the claim. The word ‘comprising’ does notexclude the presence of other elements or steps then those listed in aclaim. Furthermore, the terms “a” or “an,” as used herein, are definedas one or more than one. Also, the use of introductory phrases such as“at least one” and “one or more” in the claims should not be construedto imply that the introduction of another claim element by theindefinite articles “a” or “an” limits any particular claim containingsuch introduced claim element to inventions containing only one suchelement, even when the same claim includes the introductory phrases “oneor more” or “at least one” and indefinite articles such as “a” or “an.”The same holds true for the use of definite articles. Unless statedotherwise, terms such as “first” and “second” are used to arbitrarilydistinguish between the elements such terms describe. Thus, these termsare not necessarily intended to indicate temporal or otherprioritization of such elements. The mere fact that certain measures arerecited in mutually different claims does not indicate that acombination of these measures cannot be used to advantage.

While certain features of the invention have been illustrated anddescribed herein, many modifications, substitutions, changes, andequivalents will now occur to those of ordinary skill in the art. It is,therefore, to be understood that the appended claims are intended tocover all such modifications and changes as fall within the true spiritof the invention.

Those skilled in the art to which this invention pertains will readilyappreciate that numerous changes, variations and modifications can bemade without departing from the scope of the invention mutatis mutandis.

I claim:
 1. A pool cleaning robot comprising: a housing; an openingformed in the housing; an impeller that is configured to rotate and toinduce fluid to flow through the pool cleaning robot; a filter forfiltering fluid that flows through the pool cleaning robot; and whereinthe filter and the impeller are configured to concurrently exit the poolcleaning robot through the opening.
 2. The pool cleaning robot accordingto claim 1 wherein the impeller is configured to rotate about an axisthat is located at a center of the filter.
 3. The pool cleaning robotaccording to claim 1 wherein the opening is formed in a bottom of thehousing.
 4. The pool cleaning robot according to claim 1 wherein theopening is formed in an upper portion of the housing.
 5. The poolcleaning robot according to claim 1 wherein the filter is positionedwithin the housing and above the impeller.
 6. The pool cleaning robotaccording to claim 1 wherein the filter is positioned within the housingand below the impeller.
 7. The pool cleaning robot according to claim 1comprising a motor that is configured to rotate the impeller.
 8. Thepool cleaning robot according to claim 7 wherein the motor is alsoconfigured to rotate a filter core of the filter.
 9. The pool cleaningrobot according to claim 1 comprising connecting elements for holdingthe filter within the housing.
 10. The pool cleaning robot according toclaim 1 wherein the opening has shape that equals a shape of a base ofthe filter, wherein the opening is larger than the base of the filter.11. The pool cleaning robot according to claim 1 wherein the opening hasshape that equals a shape of a base of the impeller, wherein the openingis larger than the base of the impeller.
 12. The pool cleaning robotaccording to claim 1 wherein the filter comprises a filter housing,wherein a normal projection of the impeller on a bottom of the housingis surrounded by a normal projection of the filter housing on a bottomof the housing.
 13. A pool cleaning robot comprising: a housing; anopening formed in the housing; an impeller that is configured to rotateand to induce fluid to flow through the pool cleaning robot; a filterfor filtering fluid that flows through the pool cleaning robot; andwherein at least one element of the filter and the impeller isconfigured to exit the pool cleaning robot through the opening; andwherein the opening is formed in a side portion of the housing, whereinthe side portion of the housing differs from a top of the housing and abottom of the housing.
 14. A method for operating a pool cleaning robot,the method comprises: rotating an impeller of the pool cleaning robotand inducing fluid to flow through the pool cleaning robot; filteringthe fluid by a filter of the pool cleaning robot; and concurrentlyremoving the filter and the impeller through an opening formed in ahousing of the pool cleaning robot.
 15. The method according to claim 14comprising inserting the at least one element through the opening. 16.The method according to claim 14 wherein the removing comprisesreleasing the filter and the impeller from any other part of the poolcleaning robot.
 17. The method according to claim 14 wherein theremoving is executed without unscrewing the filter and the impeller. 18.The method according to claim 14 wherein the opening is formed in theside portion of the housing.
 19. The method according to claim 14wherein the rotating comprises rotating the impeller about an axis thatis located at a center of the filter.
 20. The method according to claim14 wherein the filter comprises a filter housing, wherein a normalprojection of the impeller on a bottom of the housing is surrounded by anormal projection of the filter housing on a bottom of the housing.